Computer reset mechanism



March 31, 1953 R. H. HILL ET AL COMPUTER RESET MECHANISM 2 SHEETS-SHEET 1 Filed June 27, 1947 R. H. HILL ETAL COMPUTER RESET MECHANISM March 31, 1953 2 SHEETSSHEET 2 Filed June 27, 1947 Patented Mar. 31, 1953 COIVIPUTER RESET MECHANISM Robert H. Hill and Charles M. Keepers, Fort Wayne, Ind., assignors to Tokheim Oil Tank and Pump Company, Fort Wayne, Ind., a corporation of Indiana Application June 27, 1947, Serial No. 757,486

17 Claims.

This invention relates to computing devices and more particularly to reset mechanisms for liquid fuel pumps of the computer type.

It is common practice to reset the computer head of a liquid dispensing unit, such as a gasoline pump, manually prior to the initiation of a dispensing operation in order that the purchaser of the delivered fuel will be charged a correct amount therefor. Automatic reset mechanisms have been proposed for the purpose of eliminating the :manual reset operation, at least in part, but such devices have not been adapted for ready installation on dispensing units without substantial modification thereof.

An object of this invention is to provide an improved reset mechanism which may be easily installed on existing forms of dispensing units and which does not require any changes in or additions to the plumbing on such units.

A further object is to provide an improved reset mechanism of simple and economical design which insures that the resetting operation must be completed before any fuel can be delivered by the dispensing unit.

A still further object is to eliminate control valves in the fuel discharge lines and other special fittings and parts which are required in prior types of reset mechanisms.

Still another object is to provide an improved electrical reset for a computer head which incorporates all of the foregoing features and advantages.

Various other objects, advantages and features of the invention will be apparent from the following specification when taken in connection with the accompanying drawings wherein a certain preferred embodiment is set forth for purposes of illustration.

In the drawings, wherein like reference numerals refer to like parts throughout:

Fig. l is a view of a gasoline computer pump equipped with a reset mechanism constructed in accordance with and embodying the principles of the invention;

Fig. 2 is a section on the line 2- -2 in Fig. 1 showing the details of construction of a clutch mechanism;

Fig. 3 is a sectional view taken substantially on the line 33 in Fig. 2; and

Figs. 4, 5, 6 and 7 are schematic wiring diagrams of the reset mechanism under various conditions of operation.

In present commercial types of gasoline computer pumps, the computer mechanism requires a one and one-eighth forward turn of the reset shaft in the performance of the resetting operation. The reset shaft thereupon comes against a positive stop and is then returned through a oneeighth turn in the reverse direction by spring .means in the computer, which builds up a torque during the final one-eighth forward turn of the shaft. The reverse one-eighth turn of the reset shaft serves to raise the shutters which mask the numeral wheels during the resetting operation.

Referring now to the drawings in detail, there is shown in Fig. 1 a conventional dispensing pump 10 of the computer type. The computer head .12 of the pump 10 has a reset shaft M which projects laterally therefrom. In accordance with the present invention, an electrical reset mechanism is is connected through the medium of a clutch it to the reset shaft I4. The supporting means for the reset mechanism I6 is omitted from this View.

The details of the clutch are shown in Figs. 2 and 3. A drive shaft 20, which in the present instance is actuated by a motor in the reset mechanism I 6, is rigidily connected to a collar 22 which in turn is welded or otherwise secured to a shell-like housing 24. The housing 24 has a punched-in ear 26 to which one end of a coil spring 28 is connected. The other end of the spring 28 is attached to a tail 3!) of a pawl 32 pivotally mounted on the housing 24 as indicated at B l. The pawl 32 carries a roller 36 which rides on the periphery of a cam 38 integral with a hub 40 which is rotatably mounted on the end of the driving shaft 20.

The hub 40 terminates in an axially extending, slotted sleeve 44 which is part of a universal connection between the hub 40 and the computer reset shaft M, Fig. l. The cam 38 is provided with a shoulder 46 adapted to be engaged by the roller 35 on the pawl 32. So long as the computer reset shaft is free to turn, the tension of the spring 23 acting on the pawl 32 is sufficient to maintain the roller 56 seated on the low portion of the cam 38 when the drive shaft 20 is operating. When the reset shaft encounters a positive stop, however, the roller 36 rides up on the shoulder 46 to disengage the clutch and to permit the aforesaid one-eighth reverse turn of the reset shaft.

The illustrated arrangement is such that the computer head I 2 must be reset before any gasoline can be dispensed by the unit ID. A switchoperating lever 50 extends from the reset mechanism i6 and is adapted to be actuated in the manner described hereinafter. To reset the computer l2 the switch lever 59 is thrown to its on position, thereby closing a master switch 52, Figs.

4 and 5, in the reset mechanism id. The initial positions of the parts when the switch 52 is open are illustrated in Fig. 4. Immediately upon closure of the switch 62, as shown in Fig. 5, a circuit is established from a current supply wire 55 through the switch 52, coil of relay 56 and contacts 5B of another relay cc to the other line wire 62. Relay 56 energizes and closes its contacts M, thereupon establishing a circuit from wire 54 through switch 52 and contacts as to the reset motor 55. The motor 66 operates and, through the medium of gearing indicated at 68, rotates the pawl or driving clutch member 32. The roller 36 rides on the periphery of the cam 33 until it encounters the shoulder d6, whereupon the cam or driven clutch member 33 commences to rotate with the driving member 32. It will be recalled that the cam 38 is connected to the reset shaft i l of the computer 52, Fig. 1. Therefore, the computer reset shaft is driven by the motor 66 through the medium of the clutch i8.

When the reset shaft of the computer has rotated through one and one-eighth turns, it encounters a positive stop in the computer head. This condition is illustrated in Fig. 6, wherein the cam 38 is arrested in the position shown, causing the roller 36 to ride up on the shoulder 46. A switch if! has a plunger 12 which is so disposed as to be actuated by the roller 3t when the cam 38 is arrested and the roller 36 passes over the shoulder M. This action causes the switch iii to close so that a. circuit is established from supply wire 54 through switch 52, coil of relay Eli, and switch 1a to the supply wire s2. Thus, closure of switch is causes relay 66 to energize, opening its contacts 58 and closing its contacts is. Opening of relay contacts 58 brings about the deenergization of relay 56 causing relay contacts 76 to close and contacts 54 to open. As relay contacts 64 open, the reset motor 65 is deenergized. Closure of relay contacts i6 establishes or conditions the circuit to the pump motor it for delivering fuel through the meter ii, dispensing hose 9 and nozzle 32.

Preferably the switch-operating lever 58 is arranged to be actuated by a nozzle support lever 84 so that the nozzle 82 must first be removed from its hook before the master switch 52 can be closed. When the nozzle 82 is restored to its hook or support lever es, the master switch 52 automatically opens. We also contemplate the employment of alternative or additional switching means such as, for instance, coin-controlled switches and the like in keeping with the principles of the invention.

As the clutch I8 is disengaged, the reset shaft 14, Fig. l, is free to be restored by the spring in the computer head i2, which causes the reset shaft and cam 38 to travel through a one-eighth reverse turn for clearing the shutters from the numeral wheels. The final rest position of the cam 38 is illustrated in Fig. 7. The driving clutch member 32 travels a short distance during the time that the reset motor 56 is coasting to a stop. Because of the friction in the gearing 68 and the motor bearings, the amount of coasting is relatively small, and moreover, the gear reduction ratio is such that the driving clutch member travels only a relatively short distance following the opening of the relay contacts 64.

It is necessary that the relay 68 be maintained energized after the driving clutch roller 36 passes out of engagement with the plunger l2 and the switch 16 opens, in order that the relay 56 will be prevented from re-energizing and prematurely interrupting the operation of the pump motor 13. To this end, there is provided a holding circuit for the relay 6t, such holding circuit being established through the relay contacts 74, relay coil 66 and switch 52. Hence, so long as the switch 52 remains closed, the relay ec remains energized. When the switch handle 55] is moved to its off" position to stop the pump motor it, the relay 6D is deenergized, and the reset mechanism assumes the condition illustrated in Fig. 4.

One of the advantages of the present invention is that it insures the completion of the resetting operation, once started, before any fuel can be delivered by the pump. Thus, for example, if the switch 52 is momentarily closed, then opened and thereafter closed again, the relay 56 goes through a corresponding cycle of energization, deenergization and re-energization so long as the relay 60 remains in a deenergized condition. Hence the relay contacts it will open each time the switch 52 is closed, thereby to prevent the circuit for the pump motor '58 from being definitely established, until the relay 6d becomes energized at the end of the resetting operation. It is impossible, therefore, to cause faulty operation of the computer by opening the master switch and then reclosing the .same before the resetting operation is completed.

From the foregoing it is apparent that I have provided an electrical reset mechanism which fulfills the above-stated objects of the invention. Obviously various modifications may be made in the illustrated embodiment without departing from the spirit of the invention. Accordingly, the invention is not limited to the details herein illustrated and described but only as indicated in the following claims. I

The invention is hereby claimed as follows:

1. In a liquid dispensing apparatus having a pump and a computer provided With a reset shaft, the combination comprising actuating means for said reset shaft, coupling means between said actuating means and said reset shaft including a driving portion operatively connected to said actuating means and a driven portion connected to said reset shaft for rotation therewith, a first control device having a plurality of operating positions and effective when in one of its said positions to permit operation of said pump and when in another of its said positions to prevent operation of said pump, a second control device having a plurality of operating positions and effective when in one of its said positions to place said first control device in its pumpoperating position and effective when in another of its said positions to place said first control device in its other position, said driving and driven portions of said coupling means being capable of relative movement when said reset shaft is positively arrested, and. an operating element for said second control device responsive to relative movement of said driving and driven parts, when said reset shaft is arrested, for placing said second control device in its first said position.

2. In a liquid dispensing apparatus having a pump and a computer provided with a reset shaft, the combination comprising a reset motor, a clutch between said motor and said reset shaft, a first relay effective when deenergized to permit operation of said pump, said reset motor being arranged to operate while said first relay is energized, a second relay effective when deenergized to permit energization of said first relay and effective when energized to deenergize said first relay, said clutchbeing adapted to disensponse: to disengagement of said clutch,

3. The combination set forth in claim 2-, further comprising a master switch for energizing said first relay when said second relay is deenergized and. for operating said pump when said first relay is deenergized, and a holding circuit. for said secand relay controlled by the first said switch and said master switch.

4. In a liquid dispensing apparatus having a pump and a computer provided with a reset shaft, the combination comprising actuating means, coupling means between said actuating means and said reset shaft, a master control element settable to an operative position for enabling operation of said actuating means and. said fuel pump, a first control device having a plurality of positions and effective when in one of its said positions to prevent operation of said actuating means and to permit operation of said pump, said first control device being eifective when in another of its. said positions to prevent operation of said pump and to permit operation of. said actuating means, a, second control, device having a plurality of positions and effective when in one of its said positions to place said first control device in its first said. position and effective. when in another of its said positions to place said first control device in its second said position, and. an operating. element for said second control device responsive to movement of said reset shaft, for. maintaining said second control device in its second said position whil the resetting operation is partially completed and for placing said second control device in its first saidposition whentheresetting operation is completed.

5. In a liquid dispensing apparatus having a pump, a motor for the pump, and a computer provided with a reset shaft, the combination comprising a reset motor, coupling means between said reset motor and said reset shaft, a master switch settable for conditionally establishing alternative circuits respectively to oper ate said reset motor and said pump motor, a first relay effective when operated to complete the circuit for operating said reset motor and efiec ti've when not operated to complete the circuit for operating said pump motor, a second relay effective when not, operated to permit energization of said first relay in response to each setting of said master switch. to. its circuit-conditioning relation and effective when operated to prevent operation of said first relay, and a control element responsive to movement of said reset shaft for operating said second relay when the resetting operation is completed.

6. The combination set. forth in claim. 5, further comprising a holding circuit for maintaining said second relay operated so long as said master switch is in its circuit-conditioning relation.

7. In a liquid dispensing apparatus having a pump and a computer provided with a reset shaft, the combination comprising a master switch, a motor, coupling means between said motor and said. shaft, first electrical contact means, means for closing said first electrical contact means in response to closure of said master switch for closing a circuit to said motor, pump disabling means to prevent operation of the pump while said motor is operating, and second electrical contact means responsive to movement of said reset shaft for removing said motor from the cir- '6 cuit when. the resetting operation. is completed.

8. In a liquid dispensing apparatus. having a pump and. a computer provided with a reset shaft, the combination comprising a master switch, a reset motor, a clutch coupling said reset motor to said shaft, said clutch including a driven member rigidly connected to said reset shaft and a driving member capable of shifting out of engagement with said driven member when said reset shaft encounters a positive stop in the computer, first electrical contact means responsive to closure of said master switch for closing a circuit to said reset motor, pump disabling means to prevent operation of the pump while said reset motor is operating, and second electrical' contact means responsive to the shifting of said driving clutch member out of engagement with said driven clutch member for removing'said reset motor from the circuit.

9. In a liquid dispensing apparatus having a motornriven pump and a computer provided with a reset shaft. the combination comprising a master switch, a reset motor, means coupling said reset motor to said shaft, a first relay having first contacts closable when said first relay is energized and second contacts closable when said first relay is deenergized, a second relay having third contacts closable when said second relay is deenergized, said, first relay and said third contacts being connected in a circuit with said master switch whereby said first relay is energized by closure of said master switch when said second relay is deenergized,. said reset: motor and said first contacts being connected in a circuit with said master switch whereby said reset motor is energized by closure of said master switch when relay is energized, said second contacts being connected in a circuit with said master switch and, the pump motor whereby the pump motor is operated by closure of said second contacts when. said master switch is, closed, and secand switching, means responsive to movement of said. reset shaft and including fourth contacts clcsable when the resetting operation is completed, said fourth contacts being connected in a circuit with said second. relay and saidmaster switch whereby said second relay is energized by closure of said fourth contacts when said master switch is closed.

1.0. In a liquid dispensing. apparatus having a motor-driven pump and a computer provided withv a reset shaft, the combination comprising a master switch. a reset motor, means. coupling said reset motor to said shaft, a first relay having first contacts closable when said firstv relay is energized and second contacts closable. when said first relay is deenergized, a second; relay having third contacts closable when saidv second relay is deenergi'zed andv fourth contacts closable when said second relay is energized, said first relay and said third contacts being connected in a circuit with said master switch whereby said first relay is energized by closure of said master switch when said second relay is deenergized, said reset motor and said first contacts being connected in a circuit with said master switch whereby said reset motor is ener gized by closure of said master switch when said first relay is energized, said second contacts being connected in a circuit with said master switch and the pump motor whereby the pump motor is operated by closure of said second contacts when said master switch is closed, second switching means responsive to movement of said reset shaft and including fifth contacts momentarily closable when the resetting operation is completed,

aeeaccs said fifth contacts being connected in a circuit with said second relay and said master switch whereby said second relay is energized by closure of said fifth contacts when said master switch is closed, and a holding circuit for said second relay including said master switch and said fourth contacts whereby said second relay is maintained energized following the opening of said fifth contacts.

11. The combination set forth in claim 10.. wherein said coupling means comprises a driven member rigidly connected to said computer reset shaft, and a driving member capable of shifting out of engagement with said driven member when said reset shaft is positively arrested, said second switching means being actuated by the shifting of said driving member to close said fifth contacts.

12. In a liquid dispensing apparatus, the combination of a pump and a computer provided with a reset shaft, electrical switching means, a motor, coupling means including a clutch between said motor and said shaft, said clutch comprising a driving member, a cam member on said reset shaft and a spring biased pawl on said driving member and driving said cam, and means engageable by said pawl upon disengagement of said clutch for operating said electrical switching means to dc-energize said motor and to energize said pump.

13. In a liquid dispensing apparatus the combination of a pump and a computer provided with a reset shaft, actuating means, motor means, clutch means including disengageabl-e parts relatively movable radially and disposed between said motor means and said reset shaft, means responsive to a change in condition of said actuating means to start operation of said motor means, means precluding operation of said pump during operation of said motor means, and means responsive to relative radial move ment of said clutch parts upon disengagement of said clutch parts to terminate the operation of said motor means and to actuate said pump.

14. In a liquid dispensing apparatus, the combination of a pump and a computer, actuating means, motor means, means responsive to a change in condition of said actuating mean to start operation of said motor means, clutch means disposed between said motor means and said reset shaft, said clutch means comprising a driving portion including a resiliently biased pawl having a cam-follower member and a driven portion including a cam having a shoulder, and a member engaging said cam follower member and. responsive to movement thereof on said cam to terminate the action of said motor means and to actuate said pump.

15. In a liquid dispensing apparatus having a pump and a computer provided with a reset shaft,the combination comprising a reset motor, means for driving said reset shaft from said reset motor, a first relay effective when deenergized to permit operation of said pump, said reset motor being arranged to operate while said first relay is energized, a second relay effective when deenergized to permit energization of said first relay and effective when energized to 'deenergize said first relay, and a switch arranged to close an operating circuit for said second relay in response to positive arresting of said reset shaft.

16. In a liquid dispensing apparatus having a pump and a computer provided with a reset shaft, the combination comprising a reset motor, coupling means between said reset motor and said reset shaft including a driving portion operatively connected to said actuating means and a driven portion connected to said reset shaft for rotation therewith, a first relay effective when deenergized to permit operation of said pump, said reset motor being arranged to operate while said first relay is energized, a second relay effective when deenergized to permit energization of said first relay and effective when energized to deenergize said first relay, the driving portion and driven portion of said coupling means being adapted to move relatively when said reset shaft is positively arrested, and a switch arranged to close an operating circuit for said second relay in response to relative movement of the driving portion and the driven portion of said coupling means.

17. In a liquid dispensing apparatus, a pump, a pump motor, a computer having a reset shaft, a reset motor, coupling means between said reset motor and said shaft, a control member, first electrical means for completing a circuit to place said reset motor in an energized circuit, means for operating said first electrical means in response to operation of said control member, pump disabling means to prevent operation of said pump motor while said reset motor is operating, means responsive to movement of said reset shaft for opening said first electrical means to de-energize said reset motor when the resetting operation is completed, and second electrical means responsive to movement of said reset shaft for energizing said pump motor when the resetting operation is completed.

ROBERT E. HILL. CHARLES M. KEEPERS.

REFERENCES CITED UNITED STATES PATENTS Name Date Hazard Feb. 22, 1938 Number 

